Printing plate locking



Aug. 12, 1941. D. w. COY

PRINTING PLATE LOCKING Filed June 28, 1939 Patented Aug. 12, 1941 TES PATENT OFFICE PRINTING PLATE L CKIN G Application June 28, 1939, Serial No. 281,671

'7 Claims. (01. 101-385) This invention relates to improvements in printing equipment and more particularly to an improved arrangement for locking printing plates, for example, electrotypes in predetermined position on a bed plate, and more particularly, but not exclusively, to means for locking such printing plates in predetermined position on a printing cylinder.

The main objects of the invention are to provide a locking arrangement of the character indicated which will be relatively inexpensive as compared with present practical and conventional devices and arrangements for accomplishing the same purpose; to provide means of the character indicated which will be universal in its adaptability to various types and sizes of printing plates and printing rolls or cylinders; and in general it is the object of the invention to provide an improved printing plate locking arrangement.

Other objects and advantages of the invention will be understood by reference to the following specification and accompanying drawing, wherein there is illustrated a printing plate locking arrangement embodying a selected form of the invention.

In the drawing:

Figure l is an elevation illustrating the improved method of locking an electrotype on the surface of a printing cylinder;

Figure 2 is a cross section on an enlarged scale on the line 22 of Figure 1; and

Figure 3 is an elevation on the plane indicated by the line 33 of Figure 2.

Referring now to the drawing, a printing roller or cylinder is designated in its entirety by the reference numeral 5 and a printing plate or electrotype 6 is shown positioned and lockedin place on the surface of the cylinder by means of a series of locks respectively designated 1. Each of the locks may be of identical construction and they may be used in such number and in such location with reference to the periphery of the printing plate as may be deemed best suited to effectively lock the plate in place.

The locks 1 may be of any of the commercially available types, the one shown herein embodying a head 8, a shank 9 and an inner end portion I t. The head 8 is preferably provided with a bevelled or undercut side H which is adapted to cooperate as best shown in Figure 2, with edge portions of the printing plate for holding the same in fixed position on the cylinder 5. The shank 9 is equipped with the device indicated at [2 which is adapted to be adjusted by means of a screw I3 for expanding the effective crosssectional dimension of the shank for: locking purposes, and the end portion I0 of the shank is provided with a shoulder or hook formation I4.

ings such as indicated at l5 in predetermined relationship to the periphery of the printing plate. Such openings H: are then tapped as indicated at l6.

An externally threaded bushing I! is fitted into the tapped opening, the bushing being provided with a flange l8 which is adapted to be seated in an appropriate counter-bore 19 at the outer end of the opening I5. The bushing I! has its internal diameter tapered from the outer or flange end of the bushing to its inner end for most effective cooperation with the locking device shown, and the inner end 20 of the bushing supplies a shoulder for engagement with the hook or shoulder 14 of the locking device. In other words, the bushing I! i of such length as to be adapted to receive the expansible stem portion 9 of the lock, with the head part 8 thereof exposed in the operative position and with the inner end hook M of the lock anchored against the inner end of the bushing.

Bymeans of a suitable key inserted in an opening, such as indicated at 2| in the lock, the screw 13 may be rotated to effect adjustment of the expanding element l2, so as to urge the head 8 against the adjacent edge portion of the printing plate 6. As shown in Figure 2, the lock 1 at the left hand side of the printing plate has been adjusted towards the right nearly to its limits of adjustment in that. direction, whereas, the lock shown at the right hand side of the printing plate, although tightly engaging the edge of the printing plate remains spaced as indicated at 22 from the wall of the bushing so that it could, except for its engagement with the printing plate, be adjusted still further towards the left. Thus it will be apparent that although the bushings l 'l are seated in fixed position, the locking memhers I are nevertheless capable of sufficient adjustment to permit minor adjustment of the plate position to be made, so that the arrangement of the fixed bushings imposes no objectionable limitations in respect of required adjustability of the plate position.

The described construction is particularly advantageous where a very large volume of like printing is to be done, for example, in c0nnec tion with the making of cartons or boxes for food or other products which are distributed in large volume. Under such circumstances, the box maker who also prints the boxes or cartons may effect substantial savings in cost of printing equipment by eliminating the relatively expensive conventional bed plates or cylinders and substituting the plain bed plates or cylinders which may be drilled and tapped as required for the particular job in mind.

Changes may be made in the described construction without departing from the spirit of the invention, the scope of which should be determined by reference to the following claims, the same being construed as broadly as possible consistent with the state of the art.

I claim:

1. In printing equipment, the combination of a cylindrical bed plate having an aperture therein, a lock having a hook adjacent its lower end, a head adjacent its upper end and an expansible means intermediate its ends, and a bushing in said aperture, said bushing being adapted to receive said lock, having its inner end provided with a shoulder portion for cooperating with said hook to prevent withdrawal of said lock, said bushing having a wall portion adapted to be engaged by said expansible means, and said lock head projecting beyond the outer end of said bushing and being adapted to engage a portion of the printing plate to position the same on said bed.

2. In the art of printing, means for looking a printing plate to a bed plate comprising the combination of an expansible lock having a headed outer end for engaging the printing plate and a hooked inner end for anchoring the lock, and a bushing for receiving the expansible portion of said lock and having an internal diameter suitable for cooperating with said portion, said bed plate having an opening for receiving said bushing and the latter being of such length that the hooked inner end of said lock is adapted to engage the inner end of the bushing to prevent outward withdrawal of the look from the bushing while said head projects beyond the outer end of thebushing so as to be engageable with a printing plate.

3. In the art of printing, means for looking a printing plate to a bed plate comprising the combination of an expansible lock having a headed outer end for engaging the printing plate and a hooked inner end for anchoring the lock, and an externally screw threaded bushing adapted to be threaded into a tapped opening in the bed plate and having an internal diameter suitable for cooperating with the expansible portion of said lock, said bushing being of such length that the hooked inner end of said lock is adapted to engage the inner end of the bushing to prevent outward withdrawal of the lock from the bushing while said head clears the outer end of the bushing so as to be engageable with a printing plate.

4. In printing equipment, the combination of a hollow printing cylinder having an aperture extending radially thereinto, a lock having a hook adjacent its lower end, a head adjacent its upper end and expansible means intermediate its ends, and a cylindrical bushing in said aperture and secured to said cylinder, said bushing being adapted to receive the expansible portion of said lock and having its inner end provided with a shoulder for cooperating with said hook to position the lock against outward endwise displacement from said bushing with the head of the lock in operative position on the surface of said cylinder.

5. In printing equipment, the combination of a cylindrical bed plate having an aperture therein, said aperture being counter-bored at its outer end, a lock having a hook adjacent its lower end, a head adjacent its upper end and an expansible means intermediate its ends, and a bushing in said aperture adapted to receive the expansible portion of said lock, said bushing having a flange at its upper or outer end adapted to be seated in the counter-bore of said opening so as to position the bushing with its outer and inner ends in predetermined relation to the surface of said bed plate, the inner end of said bushing providing a shoulder in said aperture for cooperating with said hook to operatively position the head of said lock on the surface of the bed plate and to prevent outward endwise displacement of said lock, said expansible means being adapted to engage the interior of said bushing for urging said head in printing plate clamping direction.

6. In printing equipment, the combination of a bed plate having a tapped hole therein, said hole being counter-bored at its outer end to provide an outwardly facing shoulder, an externally threaded bushing screwed into said hole, and provided with a flange at its upper or outer end seated on said outwardly facing shoulder so as to position the bushing with its outer and inner ends in predetermined relation to the surface of said bed plate, the inner end of said bushing being formed to provide an inwardly facing shoulder for cooperation with the inner end hook of a locking device having a head at its outer end, expansible means intermediate its ends and a hook at its inner end, the bushing being adapted to receive and cooperate with the expansible means of the lock for urging the head thereof in printing plate clamping direction while the inner end hook and inner end shoulder of the bushing cooperate to prevent endwise displacement of the lock from the bushing.

'7. In printing equipment, the combination of a bed plate having a tapped hole therein, an externally threaded bushing screwed into said hole, the inner end of said bushing being formed to provide an inwardly facing shoulder for cooperation with the inner end hook of a locking device having a head at its outer end, expansible means intermediate its ends and a hook at its inner end, the bushing being adapted to receive and cooperate with the expansible means of the lock for urging the head thereof in printing plate clamping direction while the inner end hook and inner end shoulder of the bushing cooperate to prevent endwise displacement of the look from the bushing.

DON W. COY. 

